Unvaccinated people more than twice as likely to contract Covid-19 again, CDC says

Unvaccinated people are more than twice as likely to be re-infected with Covid-19 than fully vaccinated people, suggests a new study, highlighting the importance of vaccines in containing the pandemic.

The study, published Friday by the Centers for Disease Control and Prevention, looked at nearly 250 Kentucky patients with Covid-19 in 2020 who tested positive again between May and June 2021. The authors compared the vaccine status of these patients along with those of nearly 500 similar people who also had an infection in 2020 but had not been re-infected until June 2021.

People who were not vaccinated were 2.34 times more likely to be re-infected than those who were fully vaccinated, the researchers found.

“If you decide you’re just going to believe that natural immunity is going to protect you, you’re more than twice as likely to get infected as people who decide to get the vaccine,” said Daniel Griffin, head of infectious diseases. to ProHealth New York’s network of health care providers, which did not participate in the study.

The researchers said they were unable to confirm the reinfection through whole genome sequencing, the gold standard. In some cases, a repeated positive test may be due to prolonged shedding of the virus or the body’s inability to clear the initial infection. But the authors also noted that the long time between the first and second positive test made reinfection the most likely explanation.